MTFCA Forum

Making progress on my new 1922. Nothing major, but lots of little things sorted out. I had it running for about an hour today and practiced driving. I am getting the hang of it and feeling more confident. But, twice today after maki g sharp right turns, the car started a serious wobble that only went away when I stopped. When I started back up, it was not there. The car is fitted with hasslers and when in wiggled the wheels, I did not find anything loose.

I am planning on checking the alignment and making sure the front wheel bearings are properly adjusted. Maybe check for play in the steering components. Any other suggestions or hints on what could be causing this?

I had the same problem on my ‘22 Coupe until I found the front end steering loose just a tiny bit. I snuggled up all the bolts and still found the drag link balls loose when grabbing the area and shaking. Added shims to the sockets and all is well now.

By all means, check the entire steering system for loose joints and loose bolts, clamps, etc. Generally speaking, wheel alignment is unlikely to cause low speed wobble. A more likely cause, espcially if the steering linkage is reasonabley tight, is wheel/tire assemblies that are out of balance and/or out of round. A car that has been sitting may have flat-spotted tires. Caster angle is important to steering stability, but it is probably not the cause of a serious low speed wobble. Loose or worn parts anywhere in the steering system and suspension, from the steering wheel to the road, can cause or aggravate shimmy/wobble. With your car sitting on the ground and the wheels pointed straight ahead, you should not be able to move the steering wheel rim more than about 1" left or right without both front wheels beginning to turn slightly.

Is the axle bent? A lot of them are. Other things might be going on. Read these posts from 2007. <http://www.mtfca.com/discus/messages/29/27467.html>

MichaelPawelek wrote: ↑

Sat Jun 18, 2022 8:31 pm

I had the same problem on my ‘22 Coupe until I found the front end steering loose just a tiny bit. I snuggled up all the bolts and still found the drag link balls loose when grabbing the area and shaking. Added shims to the sockets and all is well now.

Dont do this. This is a temporary 1/2 8$$ fix. You need to go thru every thing. Replace/replace balls & sockets.
Dont forget the steering frame bracket bushing.
Few T's get the full correct front end restoration. When they do, they are a tight pleasure to drive.

Thanks for the tips. This car was stored up on stands so the tires are fine. I will go through the steering to see what may be loose to start and see where that takes me. I am currently working on my speedster front end so I am familiar with what I am looking at.

Getting a car back on the road, even one in good general shape is always a process.

Once you have everything fitting nicely on the front axle, check the caster. If it shows the axle has too little lean back at the top, it needs correcting. This is one area where a bit more is better than not enough. If the caster varies from one side to the next, your axle is twisted. While you are at it, make sure the spring perches are oriented correctly, making the axle lean back at the top.

Hope this helps.
Allan from down under.

At the speed this occurs it will not be balance or eccentricity. It's lack of damping (friction). The usual fix is to tighten the spindle bolts just a little to add a bit of friction. But don't overdo it, and it's necessary that there is no vertical float of the stub axles in the axle forks. If there is, tightening will bend the axle.

Assume NOTHING. Check EVERYTHING.

I had two issues that caused mine to shimmy. One spring perch was twisted slightly out of alignment with the spring. That shackle would bind when the axle moved. Hitting a bump made the whole axle shift to the left. My other problem was that I had positive camber on the left and negative on the right. These are fixed now.

After you confirm that all the parts are in good condition, add a small amount of toe-in. A good way to accurately measure the toe, is to raise each wheel. Then spin the wheel as fast as you can by hand, and scribe a line on the tread. I use a jack stand close to the tire, and a soap stone or sharp screwdriver. Then set the wheels on the ground and use a tape measure to compare the scribe line on front and back of the tread, the same approximate distance from the floor. I find that Ford model T's like the front wheels one quarter of an inch toed-in. This will stop the "death wobble".

One more thing I didn't see listed. The nut which holds the spindle arm to the spindle. If it is loose it will allow the arm to move a bit.
This type of shimmy is usually harmonic, so that when you hit a pothole or maybe turn in a certain direction it starts to shake and continues until you come to a stop and start out again.
Anything loose can cause it so check out all connections.
Norm

Thanks for the tips. It is definitely a harmonic wobble. So far, the only thing I have found with play is the steering shaft in the lower bracket. When I move the steering wheel, I can see the steering arm shift from side to side. So, the bracket needs new bushings. Still some things to check.

Check your Caster. This is set by the spring perches and they are left's and right's. A couple of days ago while helping on a car I noticed the car had the correct perch on the driver side and an identical driver side perch on the passenger side! Easy to check. The centering point should be the rear. Also check with a framing square placed on the floor and against the axle should show a 1/8" gap at the top of the axle.

I believe you should have closer to a 1/4" gap at the axle top measure with a square - the old saying was "a #2 pencil should be able to be inserted at the top".

RajoRacer wrote: ↑

Sun Jun 19, 2022 12:59 pm

I believe you should have closer to a 1/4" gap at the axle top measure with a square - the old saying was "a #2 pencil should be able to be inserted at the top".

It is wider than 1/8", 6 degrees, I believe according to the manual. I like a 3/8" difference. & have gone up to 5/8" on my freeway flyer.
The T is more stable @ higher speeds.